Normal morphology of sacroiliac joints in children: magnetic resonance studies related to age and sex.
OBJECTIVE
To determine in a prospective study the normal MRI morphology of the sacroiliac joints (SIJs) in relation to age and sex during adolescence.


METHODS
A total of 98 children (63 boys, mean age 12.7 +/- 2.8 years; 35 girls, mean age 13.7 +/- 2.3 years), ranging in age from 8 to 17 years, with juvenile chronic arthritis (JCA) but without signs of sacroiliitis fulfilled the study prerequisites (no back pain and no pathologic changes of the SIJs on physical examination before MRI in a 1.5-year follow-up). An additional eight HLA-B27-negative boys and eight HLA-B27-negative girls without arthritis served as controls. The MRI protocol comprised a T1-weighted SE sequence, an opposed-phase T2*-weighted GE sequence, and a dynamic contrast-enhanced study in single-section technique.


RESULTS
Noncontrast MRI permitted differentiation of "open" from ossified segmental and lateral apophyses of the sacral wings, with a significant difference in age (P < 0.05) between children with open and ossified apophyses. Ossification of the apophyses of the sacral wings was seen significantly earlier (P < 0.05) in girls than in boys. Girls also had a significantly higher incidence of transitional lumbosacral vertebrae, pelvic asymmetries, and accessory joints. In the contrast-enhanced opposed-phase MRI study, normal cartilage of the SIJs showed no contrast enhancement whereas the joint capsule showed a moderate enhancement.


CONCLUSIONS
There are significant age- and sex-related differences in the normal MRI morphology of juvenile SIJs. Our findings might serve as a standard of comparison for the evaluation of pathologic changes--in particular for the early identification of juvenile sacroiliitis.
Bollow
M
M
Institut für Röntgendiagnostik, Charité, Humboldt-Universität zu Berlin, Germany.
Braun
J
J
Kannenberg
J
J
Biedermann
T
T
Schauer-Petrowskaja
C
C
Paris
S
S
Mutze
S
S
Hamm
B
B
D000293:Adolescent; D000375:Aging; D001171:Arthritis, Juvenile / Q000150:complications; D002358:Cartilage, Articular / Q000033:anatomy & histology; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D015796:HLA-B27 Antigen / Q000032:analysis; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D012446:Sacroiliac Joint / Q000033:anatomy & histology*; D012727:Sex Characteristics
D015796:HLA-B27 Antigen